The first goal of this article is to construct a tropical analogue \(\mathcal {J}_{g,n}^{trop}\)  of the compactified universal Jacobian \(\overline{\mathcal {J}}_{g,n}\) , which we call the tropical universal Jacobian (an object that was first envisioned in [1]}).
Following the framework of [2]}, we define \(\mathcal {J}_{g,n}^{trop}\)  as the category fibered in groupoids over the category \(\operatorname{\bf {RPC}}\)  of rational polyhedral cones whose fiber over \(\sigma \in \operatorname{\bf {RPC}}\)  is the groupoid of pairs \((\Gamma /\sigma ,D)\) , where \(\Gamma /\sigma \)  is a quasi-stable tropical curve over \(\sigma \)  of type \((g,n)\)  and \(D\)  is an admissible divisor on the underlying graph \((\Gamma )\)  of \(\Gamma \) , see Definition REF . The category \(\mathcal {J}_{g,n}^{trop}\)  comes equipped with a (forgetful-stabilization) morphism of categories fibered in groupoids
\(\begin{aligned}\Phi ^{trop}\colon \mathcal {J}^{trop}_{g,n} & \longrightarrow \mathcal {M}^{trop}_{g,n}\\(\Gamma /\sigma , D) & \longmapsto (\Gamma /\sigma )^{\operatorname{st}},\end{aligned}\) 
